Role of Imaging in the Evaluation of Patients at Risk for Sudden Cardiac Death: Genotype-Phenotype Intersection

Several monogenic cardiac disorders are associated with sudden cardiac death. These include primary electrophysiological disorders (long QT, short QT, Brugada, and catecholaminergic ventricular tachycardia syndromes) and cardiomyopathies, including hypertrophic and dilated cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy. This review presents the genotype-phenotype relations in these diseases. In addition to establishing a diagnosis, imaging can play an important role in identifying the pathophysiological abnormalities and hence the potential to guide therapy in some patients. Furthermore, imaging findings in some patients add incremental prognostic information for risk stratification of sudden cardiac death. Finally, along with genetic testing, imaging is important for screening and, in some cases, can identify subjects with positive mutations who have not yet developed the classical phenotype.